JP2004280049A - Photoresist having hydroxylated group which can be cut by photoacid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new hydroxyl ester-containing polymer composition which is useful as a base resin of a resist for photoimaging to form an image in the manufacture of a semiconductor device and for the use of a photoresist (positive-working and/or negative-working) and which has a potential as a base resin for various purposes, and to provide a photoresist having improved performance at 193 nm and 157 nm. <P>SOLUTION: The polymer composition and the photoresist are prepared by using a polymer as the base resin made functional with at least one kind of hydroxyester functional group expressed by -CO<SB>2</SB>-C(R<SP>1</SP>)(R<SP>2</SP>)-[C(R<SP>3</SP>)(R<SP>4</SP>)]<SB>n</SB>-C(R<SP>5</SP>)(R<SP>6</SP>)-OH. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to photoimaging and the use of photoresists (positive and / or negative) for imaging in semiconductor device fabrication. The present invention also relates to novel hydroxyester-containing polymer compositions that are useful as base resins for resists and potentially as base resins for many other uses.

  Polymers have been used as components of imaging and photosensitive systems, particularly in photoimaging systems (see, for example, Non-Patent Document 1). In such systems, ultraviolet (UV) radiation or other electromagnetic radiation strikes the material containing the photoactive component and causes a physical or chemical change in the material. This produces a useful image or latent image that can be processed into an image useful for semiconductor device fabrication.

  Although the polymer itself may be photoactive, the photosensitive composition typically contains one or more photoactive components in addition to the polymer. Upon exposure to electromagnetic radiation (e.g., ultraviolet light), the photoactive component acts to cause the rheological state, solubility, surface properties, refractive index, color, electromagnetic properties, or other such physical or chemical properties of the photosensitive composition. (For example, see Non-Patent Document 1).

The imaging of very fine features at the submicron level in semiconductor devices requires far ultraviolet (UV) or extreme ultraviolet (UV) electromagnetic radiation. In the manufacture of semiconductors, a positive resist is usually used. Lithography at UV 365 nm (I-line) using novolak polymers and diazonaphthoquinone as dissolution inhibitors is a currently established chip technology with a resolution limit of about 0.35 to 0.30 microns. Lithography at a far UV of 248 nm using p-hydroxystyrene polymers is known, which has a resolution limit of 0.35 to 0.18 microns. Due to the lower resolution limit with shorter wavelengths (i.e., image formation at 193 nm, resolution limit of 0.18-0.065 microns), a strong desire for photolithography at shorter wavelengths in the future There is. Photolithography using an exposure wavelength of 193 nm (obtained from an argon fluorine (ArF) excimer laser) is a strong candidate for microelectronics fabrication using future design criteria of 0.18 and 0.13 microns. Photolithography using an exposure wavelength of 157 nm (F obtained using a ₂ laser source) may be used in microelectronics fabrication using the following future design criteria 0.100 microns. Conventional near-UV and far-UV organic photoresists cannot be used in a single layer fashion at these wavelengths due to their opacity below 193 nm.

WO 00/067072 pamphlet (Feiring and Feldman, 11/9/2000) Introduction to Microlithography, Second Edition by L. F. Thompson, C.G.Willson, and M. J. Bowden, American Chemical Society, Washington, DC, 1994. E. Reichmanis et al., "The Effect of Substituents on the Photosensitivity of 2-Nitrobenzyl Ester Deep UV Resists", J. Electrochem. Soc. 1983, 130, 1433-1437. Posner et al. Tetrahedron, vol. 32, page 2281 (1976) Davies et al. J. Chem. Soc. Perkin I, page 433 (1973)

  There is a continuing need for photoresists with improved performance at 193 and 157 nm, and it is an object to provide such photoresists.

The present invention relates to polymers and photoresists that contain certain hydroxyester functionalities. Specifically, the present invention relates to a photoresist,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) with a photoactive component
And a photoresist comprising:

The invention also provides a photoresist,
a) The following formula:
_{^{H 2 C = C (X)}} -CO 2 -C (R 1) (R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer comprising at least one repeating unit derived from
[Where,
X = H, C ₁ -C ₆ alkyl, F, or F-substituted C ₁ -C ₆ alkyl;
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) a photoresist comprising a photoactive component.

The invention also relates to a copolymer,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A repeating unit comprising at least one functional group consisting of:
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) a repeating unit derived from a polycyclic ethylenically unsaturated compound;
c) a repeating unit derived from an ethylenically unsaturated compound containing at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom;
And a copolymer characterized by comprising:

The invention also provides a photoresist,
a) a polymer,
i) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A repeating unit functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
ii) a repeating unit derived from a polycyclic ethylenically unsaturated compound;
iii) a polymer comprising a repeating unit derived from an ethylenically unsaturated compound containing at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom; and b) a photoactive component. Regarding resist.

In another embodiment, the invention is a method of creating a photoresist image on a substrate, comprising, in order,
(W) a step of applying a photoresist composition to the substrate,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) at least one photoactive component;
c) applying a photoresist composition comprising a solvent and
(X) drying the applied photoresist composition to substantially remove the solvent, thereby forming a photoresist layer on the substrate;
(Y) imagewise exposing the photoresist layer to form an image-forming region and a non-image-forming region;
(Z) developing the exposed photoresist layer having imaged and non-imaged areas to form a relief image on the substrate.

The present invention also provides a coated substrate,
a) a substrate, and b) a photoresist composition,
i) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
ii) with photoactive components
Photoresist composition containing
And a coated substrate comprising:
The developing step (Z) can be a negative type or a positive type.

  The photoresist composition of the present invention has high transparency to extreme ultraviolet light, far ultraviolet light, and near ultraviolet light, high plasma etching resistance, and microelectronic device fabrication using design standards of 0.18 and 0.13 μm and below. The balance of desired properties, including suitable expected high resolution properties, is particularly excellent. The photoresist composition of the present invention has particularly excellent light transmittance at 193 and 157 nm. The novel copolymers of the present invention are also superior in properties, including the expected high transmission at 193 and 157 nm and other wavelengths of UV.

  The present invention provides polymers and copolymers that are functionalized with at least one hydroxyester functional group that can serve as a protective acid group. The polymers and copolymers of the present invention are useful as photoresist components for use at 193 and 157 nm. Such protective acid groups can generate hydrophilic acid groups that allow the development of resist coatings, especially under aqueous conditions, by the catalysis of acids or bases generated by photolysis from the photoactive component (PAC).

The hydroxyester function of the present invention has the formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]

In a preferred embodiment of the present invention,
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl or,, ^{R 1} and ^{R 2} are taken together, with the proviso that the carbon bonded to ^{R 1} and ^{R 2} are not in bridgehead positions, 5 or 6-membered Forming a ring;
R ³ , R ⁴ ＨH, C ₁ -C ₆ alkyl, or R ³ and R ⁴ together form a 5- or 6-membered ring;
R ⁵ , R ⁶ ＨH, C ₁ -C ₆ alkyl, or R ⁵ and R ⁶ together form a 5- or 6-membered ring;
n = 0, 1, 2 or 3.

_{^{Wherein, -CO 2 -C (R 1)}} (R 2) - [C (R 3) (R 4)] n -C (R 5) hydroxy ester functional group (R 6) -OH is the art It can be incorporated into polymers and copolymers in any of several ways known to those skilled in the art. For example, acid functional polymers, ^{diol, HO-C (R 1)} (R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) reacts -OH, and To form the corresponding ester.

Alternatively, the hydroxyester functional groups of the present invention can be incorporated into ethylenically unsaturated compounds that have been homopolymerized or have been polymerized with other monomers to form the desired hydroxyester-functionalized polymer. For example, _{^{acrylates, H 2 C = C (H}} ) CO 2 -C (R 1) (R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH, Can be homopolymerized or copolymerized with another acrylate to form an acrylate polymer, or can be copolymerized with another monomer such as a styrenic.

  Suitable acrylate comonomers include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, t-butyl acrylate, 2-methyl-2-adamantyl acrylate, 2-methyl-2-norbornyl acrylate, 2-methoxyethyl acrylate, Includes 2-hydroxyethyl acrylate, 2-cyanoethyl acrylate, glycidyl acrylate, 2,2,2-trifluoroethyl acrylate, as well as the corresponding methacrylate monomers. These acrylate and methacrylate monomers can also be polymerized with other ethylenically unsaturated compounds, such as fluoroolefins and polycyclic olefins.

  Suitable hydroxy esters include 2-propenoic acid, 2-hydroxy-1,1,2-trimethylpropyl ester (PinAc) and the corresponding methacrylate monomer (PinMAc), 2,5-dimethyl-2,5-hexanediol. Includes monoacrylate and monomethacrylate derivatives. Suitable hydroxy esters can also be prepared from the reductive dimerization products of various aliphatic and cycloaliphatic ketones, such as cyclohexanone, cyclopentanone and methyl ethyl ketone. It is particularly preferred that the hydroxyester is PinAc. In a preferred embodiment of the present invention, the photoresist composition further comprises a repeating unit derived from at least one polycyclic ethylenically unsaturated compound. The ethylenically unsaturated group may be contained in a polycyclic moiety such as norbornene, or may hang on the polycyclic moiety such as vinyl 1-adamantanecarboxylate.

  Suitable polycyclic ethylenically unsaturated compounds for use in the present invention include, but are not limited to, the compounds shown below.

The photoresists and copolymers of the present invention also include a repeating unit derived from at least one ethylenically unsaturated compound including a fluoroalcohol or a protected fluoroalcohol, wherein the fluoroalkyl group is present as part of the fluoroalcohol functionality. Units can be included. These fluoroalkyl groups are designated R _f and R _f ′ and can be partially or fully fluorinated alkyl groups (ie, perfluoroalkyl groups). Generally, R _f and R _f ′ are the same or different fluoroalkyl groups of 1 to about 10 carbon atoms, or they are combined to form (CF ₂ ) _n , where n is 2 To 10). (In the last sentence, the term "coalescing" means that _Rf and _Rf 'are not independent, distinct fluorinated alkyl groups, but rather form a ring structure together.)

R _f and R _f ′ are acidified to the hydroxyl group (—OH) of the fluoroalcohol functional group such that hydroxyl protons are substantially deviated in a basic medium such as aqueous sodium hydroxide solution or aqueous tetraalkylammonium hydroxide solution. It can be a partially fluorinated alkyl group without restriction, except that there must be a sufficient degree of fluorination to provide the degree. It is preferred that the fluorinated alkyl group of the fluoroalcohol functional group be sufficiently fluorinated so that the pKa value of the hydroxyl group is 5 <pKa <11. Preferably, R _f and R _f ′ are each independently a perfluoroalkyl group having 1 to 5 carbon atoms, and it is particularly preferable that both R _f and R _f ′ are trifluoromethyl (CF ₃ ). .

The structure of a suitable fluoroalcohol functionality is
—CH ₂ C (R _f ) (R _f ′) OH
Wherein R _f and R _f ′ are the same or different fluoroalkyl groups of 1 to about 10 carbon atoms or are united to (CF ₂ ) n (where n is 2 To 10).

  Representative examples of comonomers that include a fluoroalcohol functionality and are within the scope of the present invention are illustrated below, but not limited to.

  Suitable comonomers containing a fluoroalcohol functionality also include polycyclic compounds.

In a preferred embodiment of the present invention, the photoresist comprises recurring units derived from at least one ethylenically unsaturated compound comprising at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom. Representative ethylenically unsaturated compounds suitable for the present invention include, but are not limited to, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, perfluoro- (2 , 2-dimethyl-1,3-dioxole), perfluoro - _{(2-methylene-4-methyl-1,3-dioxolane), CF 2 = CFO (CF} 2) t CF = CF 2 ( where, t is 1 or 2), and R _f OCF ＝ CF _2, where R _f is a saturated fluoroalkyl group of 1 to about 10 carbon atoms. Preferred comonomers are tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, and R _f OCF = CF ₂ where R _f is a saturated fluoroalkyl group of one to about ten carbon atoms. is there.

  The following sections describe the photoresist compositions of the present invention in terms of their components.

(Photoactive component (PAC))
The photoresist composition of the present invention contains at least one photoactive component (PAC). The photoactive component is typically a compound that can supply an acid or base upon exposure to actinic radiation. A PAC is called a photoacid generator (PAG) if the acid is generated upon exposure to actinic radiation. When exposure to actinic radiation produces a base, the PAC is called a photobase generator (PBG).

  Suitable photoacid generators of the present invention include, but are not limited to, hydroxamic esters such as 1) sulfonium salts (structure I), 2) iodonium salts (structure II), and 3) structure III.

In structures ^I-II, R 7 to R ⁹ are each independently a substituted or unsubstituted aryl or substituted or unsubstituted _C 1 _{-C 20} alkylaryl, (aralkyl). Representative aryl groups include, but are not limited to, phenyl and naphthyl. Suitable substituents include, but are not limited to, hydroxyl (-OH) and _C 1 _{-C 20} alkyloxy _{(e.g., C} 10 _{H 21} O) is included. Structure I~II anions X- include, but are not limited to, SbF ₆ - (hexafluoroantimonate), _{CF 3} SO 3 - (trifluoromethylsulfonate = triflate), and _C 4 _F 9 SO ₃ - (sulfonic acid Perfluorobutyl).

(Dissolution inhibitors and additives)
In the present invention, various dissolution inhibitors can be used. Ideally, dissolution inhibitors (DIs) for far and ultra-UV resists (eg, 193 nm resists) will improve the dissolution inhibition, plasma etch resistance, and adhesion behavior of resist compositions containing a given DI additive. Should be designed / selected to meet multiple material needs, including: Certain dissolution inhibiting compounds also serve as plasticizers in resist compositions.

  A variety of bile salt esters (ie, cholate esters) are particularly useful as DIs in the compositions of the present invention. Bile salt esters have been known as effective dissolution inhibitors for short-wavelength UV resists, including the work of Reichmanis et al. In 1983 (see, for example, Non-Patent Document 2). Bile salt esters are available for a variety of reasons, including their availability from natural sources, high cycloaliphatic carbon content, and especially when they are used in the electromagnetic spectrum (substantially in the far and ultra-UV regions). It is also a particularly attractive choice for DI because it is transparent at short wavelengths and in the vacuum UV range (eg, they usually have high transmission at 193 nm). In addition, bile salt esters are attractive choices for DI, as they can be designed to be compatible over a wide range from hydrophobic to hydrophilic depending on hydroxyl substitution and functionalization.

  Representative bile acids and bile acid derivatives suitable as additives and / or dissolution inhibitors of the present invention include, but are not limited to, those exemplified below. These include cholic acid (IV), deoxycholic acid (V), lithocholic acid (VI), t-butyl deoxycholate (VII), t-butyl lithocoleate (VIII), and t-butyl-3-cotocholate. α-acetyl (IX). Bile acid esters, including compounds VII-IX, are preferred dissolution inhibitors in the present invention.

  Another class of dissolution inhibitors, such as various diazonaphthoquinones (DNQ) and diazocoumarins (DC), can be utilized in the present invention in some applications. In general, diazonaphthoquinone and diazocoumarin are suitable for resist compositions designed for imaging with long wavelength UV radiation (eg, 365 nm, and possibly 248 nm). In general, these dissolution inhibitors are not preferred in resists designed for imaging with UV radiation of 193 nm or less. This is because these compounds absorb strongly in this UV region and usually do not have sufficient transmission for most applications at these short UV wavelengths.

(Components for negative photoresist embodiment)
Some embodiments of the present invention are negative photoresists. These negative-acting photoresists include at least one binder polymer containing acid labile groups and at least one photoactive component capable of providing a photogenerated acid. When the resist is imagewise exposed, a photogenerated acid is provided which converts the acid labile group to a polar functional group (eg, from an ester functional group (low polarity) to an acid functional group (high polarity)). Conversion). Development is then performed with an organic solvent or a critical fluid (having a medium to low polarity), resulting in a negative working system in which exposed areas remain and unexposed areas are removed.

  A variety of different cross-linking agents, or optional photoactive components, can be used in the negative-working compositions of the present invention as needed. (Crosslinking agents are necessary in embodiments that result in insolubilization in the developer as a result of cross-linking, however, polar groups insoluble in medium / low polarity organic solvents or critical fluids are formed in the exposed areas, resulting in Optional in preferred embodiments that result in insolubilization.) Suitable crosslinking agents include, but are not limited to, various bis azides such as 4,4'-diazidodiphenyl sulfide and 3,3'-diazide diphenyl sulfone. included. The negative resist composition containing a cross-linking agent preferably also contains a suitable functional group (for example, an unsaturated C = C bond). This functional group can react with reactive species (eg, nitrene) generated upon UV exposure to form a crosslinked polymer that is insoluble, dispersible, or substantially swells in the developer. As a result, the composition is provided with negative-type properties.

(Other ingredients)
The compositions of the present invention can contain optional additional components. Examples of additional components that can be added include, but are not limited to, resolution enhancers, fixing agents, residue inhibitors, coating aids, plasticizers, and Tg (glass transition temperature) regulators.

(Process step)
(Imagewise exposure)
Photoresist compositions of the present invention are sensitive in the ultraviolet region of the electromagnetic spectrum, particularly ≤365 nm. Imagewise exposure of the resist compositions of the present invention can be performed at a number of different UV wavelengths, including but not limited to 365 nm, 248 nm, 193 nm, 157 nm, and shorter wavelengths. Preferably, the imagewise exposure is performed with 248 nm, 193 nm, 157 nm and shorter wavelength ultraviolet light, more preferably with 193 nm, 157 nm and shorter wavelength ultraviolet light, with 157 nm and shorter wavelength ultraviolet light. Is more preferable. Imagewise exposure can be performed digitally using a laser or equivalent device, or non-digitally using a photomask. Suitable laser devices for digital imaging of the compositions of the present invention include, but are not limited to, an argon-fluorine excimer laser with a UV output of 193 nm, a krypton-fluorine excimer laser with a UV output of 248 nm, and a 157 nm. Includes a fluorine (F ₂ ) laser with output. As mentioned above, using shorter wavelength UV radiation for imagewise exposure corresponds to higher resolution (lower resolution limit), so that shorter wavelengths (eg, 193 nm or 157 nm or less) are used. It is generally preferred to use longer wavelengths (eg, 248 nm or more).

(developing)
The resist composition of the present invention must contain sufficient functional groups for development after imagewise exposure to UV radiation. This functional group is an acid or protected acid so that aqueous development can be performed using a basic developer such as sodium hydroxide solution, potassium hydroxide solution, or ammonium hydroxide or a substituted ammonium hydroxide solution. It is preferable that The hydroxyester groups of the present invention can serve as protecting acid groups. Some polymers in the resist composition of the present invention have structural units:

At least one acid-containing or protective acid-containing monomer consisting of

Wherein E ¹ is H or C ₁ -C ₁₂ alkyl, F or CF ₃ ; E ² is CO ₂ E ³ , SO ₃ E ³ , or another acidic functional group; E ³ is H Or unsubstituted or hydroxyl-substituted C ₁ -C ₁₂ alkyl. Alkyl groups can contain 1 to 12 carbon atoms, and preferably have 1 to 8 carbon atoms. Preferred acid-containing binder polymers that can be aqueous processed (aqueous development) during use are carboxylic acid-containing copolymers. The concentration of carboxylic acid groups is determined by optimizing the amount required for good development in an aqueous alkaline developer for a given composition.

The fluoroalcohol group, if present in the polymer, can include a protecting group. The protecting group protects the fluoroalcohol group from exhibiting its acidity while in this protected form. Alpha-alkoxyalkyl ether groups are preferred protecting groups for fluoroalcohols to maintain a high degree of transparency of the photoresist composition. The structure of the resulting protected fluoroalcohol group is as follows:
—C (R _f ) (R _f ′) OCH ₂ OCH ₂ R ¹⁰
In this protected fluoroalcohol, R _f and R _f ′ are as described above, and R ¹⁰ is hydrogen or a linear or branched alkyl group of 1 to 10 carbon atoms. By way of example, and not limitation, an example of an α-alkoxyalkyl ether group is methoxymethyl ether. The fluoroalcohol having this protective group is obtained by reacting the fluoroalcohol with chloromethyl methyl ether.

  When an aqueous-processable photoresist is coated or otherwise applied to a substrate and imagewise exposed to UV radiation, the binder material must have sufficient acid groups (eg, carboxylic acid) for development of the photoresist composition. An acid group) and / or a protective acid group that is at least partially deprotected on exposure, so that the photoresist (or other photoimageable coating composition) can be processed in an aqueous alkaline developer. is necessary. In the case of a positive photoresist layer, portions of the photoresist layer that have been exposed to ultraviolet light are removed during development, while unexposed portions are completely exposed to an aqueous solution containing 0.262 N tetramethylammonium hydroxide (typically 120 at 25 ° C.). Second development) or 1% by weight sodium carbonate (development at a temperature of 30 ° C., usually less than 2 minutes) is substantially unaffected during development with an aqueous alkaline solution. In the case of a negative photoresist layer, portions of the photoresist layer that have not been exposed to UV radiation are removed during development, but the exposed portions are substantially affected during development using a critical fluid, an organic solvent, or an alkaline aqueous solution. Not receive.

  As used herein, a critical fluid is one or more substances heated to a temperature near or above its critical temperature and compressed to a pressure near or above its critical pressure. The critical fluid of the present invention is at least at a temperature greater than 15 ° C. below the critical temperature of the fluid and at least at a pressure greater than 5 atmospheres below the critical pressure of the fluid. Carbon dioxide can be used as the critical fluid of the present invention, including its use as a developer. Various organic solvents can be used as the developer of the present invention. These include, but are not limited to, halogenated solvents and non-halogenated solvents. Halogenated solvents are preferred, and fluorinated solvents are more preferred.

(substrate)
Substrates used in the present invention include silicon, silicon oxide, silicon nitride, silicon oxynitride, and various other materials used in semiconductor fabrication.

Glossary
Analysis / measurement bs broad singlet δ NMR chemical shift measured in specified solvent g gram NMR nuclear magnetic resonance
¹ H NMR proton NMR
¹³ C NMR ¹³ C NMR
¹⁹ F NMR Fluorine ¹⁹ NMR
s singlet sec. Seconds m Multiline mL Milliliter mm Millimeter T _g Glass transition temperature M _n Number average molecular weight of given polymer M _w Weight average molecular weight of given polymer P = M _w / M _n Polydispersity of given polymer Absorption coefficient AC = A / b, where absorbance A = Log ₁₀ (1 / T), and
b = film thickness (microns), where T = transmittance defined below.
Transmittance Transmittance T = transmitted through the sample relative to the radiation intensity incident on the sample
It is a ratio of radiation intensity and is measured at a specified wavelength λ (eg, nm).

Chemicals / monomer MAdA 2-methyl-2-adamantyl acrylate (2-propenoic acid,
2-methyltricyclo [3.3.1.13,7] dec-2-
Ill ester)
[CAS registration number 249562-06-9]
OHKA America, Inc. , Milpitas, CA
MEK 2-butanone
Aldrich Chemical Co. ,
Milwaukee, WI
Perkadox® 16N peroxydicarboxylic acid
Di- (4-t-butylcyclohexyl)
Oury Chemical
Corp .. , Burt, NY
PGMEA Propylene glycol methyl ether acetate
Aldrich Chemical Co. ,
Milwaukee, WI
PinAc 2-propenoic acid, 2-hydroxy-1,1,2-trimethyl
Propyl ester [CAS registration number 97325-36-5]
Solkane 365mfc 1,1,1,3,3-pentafluorobutane
Solver Fluor, Hanover,
Germany
t-BuAc t-butyl acrylate
Aldrich Chemical Co. ,
Milwaukee, WI
TCB trichlorobenzene
Aldrich Chemical Co. ,
Milwaukee, WI
TFE tetrafluoroethylene
E. FIG. l. du Pont de Nemours and
Company, Wilmington, DE
THF tetrahydrofuran
Aldrich Chemical Co. ,
Milwaukee, WI

  NB-OAc and NB-OH were prepared as described in the literature (for example, see Non-Patent Documents 3 and 4). NB-F-OH, NB-F-OMOM, NB-Me-F-OH and NB-Me-F-OMOM were prepared as described in the literature (see, for example, Patent Document 1).

ultraviolet
Extreme UV Ultraviolet electromagnetic spectrum in the range of 10 nm to 200 nm
Region Far UV Ultraviolet electromagnetic spectrum in the 200 to 300 nanometer range
Ultraviolet electromagnetic spectrum in the range UV 10 nm to 390 nm
Region Near UV Ultraviolet electromagnetic spectrum in the 300-390 nanometer range
region

(Example)
Unless otherwise specified, all temperatures are in degrees Celsius, all mass measurements are in grams, and all percentages are weight percentages.

  Unless otherwise specified, n in the structures described in the examples represents the number of repeating units of the polymer. Throughout the specification, p in the structure represents the number of repeating units of the polymer.

The glass transition temperature (T _g ) was determined by DSC (differential scanning calorimetry) using a heating rate of 20 ° C./min. Data was reported from the second heat. The DSC unit used was a Model DSC 2910 manufactured by TA Instruments, Wilmington, DE.

The term “clearing dose” refers to the minimum exposure energy density (eg, in units of mJ / cm ² ) at which a given photoresist film can be developed after exposure.

(Synthesis of PinAc from pinacol and acryloyl chloride)
In a 3-neck round bottom flask equipped with an overhead stirrer, dropping funnel, reflux condenser, nitrogen atmosphere, and thermowell, add pinacol (23.6 g, 0.20 mol), ether (150 mL), and triethylamine (10.6 g, 0 .105 mol; freshly distilled). Acryloyl chloride (9.05 g, 0.10 mol) was added dropwise at room temperature (22 ° C. to 27 ° C.), and the addition rate was adjusted to absorb the exotherm. The mixture was stirred at room temperature for 18 hours.

This mixture was added to cold water (100 mL), and the whole amount of the obtained mixture was filtered. The organic layer was washed with additional water (50 mL), dried _{(Na 2 SO 4, MgSO 4} ), to give a yellow oil 5.8g and stripped. Kugelrohr distillation gave 3.44 g of a boiling point of 35-45 ° C./0.05 mm and about 1.0 g of a boiling point of 60-80 ° C./0.5 mm.

NMR (C ₆ D ₆ ) of the crude yellow oil was consistent with an approximately 2/1 mixture of the desired ester / residual diol, contaminated with approximately 6 mol% bisacrylate.
Washed with water to remove residual pinacol.

(Synthesis of PinAc from pinacol and acryloyl chloride)
A 3-neck round bottom flask equipped with an overhead stirrer, dropping funnel, thermowell, and nitrogen atmosphere was charged with pinacol (47.2 g, 0.40 mol) and ethylene glycol dimethyl ether (175 mL). The solution was cooled to −15 ° C., and a methyllithium ether solution (125 mL, 1.6 M, 0.20 mol) was added dropwise. After the addition was complete, the mixture was warmed to 0 ° C. and stirred for 10 minutes. The mixture was cooled to −20 ° C. and acryloyl chloride (19.0 g, 0.21 mol) was added dropwise over 0.5 hours. After holding at −20 ° C. for 15 minutes, a mixture of 0.5 g of phenothiazine, 0.5 g of monomethylhydroquinone and 0.1 g of TEMPO was added. Water (4 mL) was then added dropwise to the mixture, warmed to 0 ° C. and stirred for 15 minutes before work-up.

The mixture was filtered (N ₂ pressure) to remove solids. The solid was washed with additional ether (75 mL) and the ether was combined with the first filtrate. Another one of the mixture of 0.5 g of phenothiazine, 0.5 g of monomethylhydroquinone and 0.1 g of TEMPO was added to the filtrate. Evaporation gave 28.4 g of a deep yellow oil. This was evaporated on a Kugelrohr to give 17.3 g of a colorless oil having a boiling point of 45 to 55 ° C / 0.2 mm. ¹ H NMR showed about 92% monoadduct and about 8% bis (acrylate). The Kugelrohr evaporating material obtained by combining the two operations was subjected to rotary band distillation to obtain 17.1 g of a pure product having a boiling point of 40 to 42 ° C / 0.05 mm.

(Polymer of TFE, NB-F-OH and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 71.05 g of NB-F-OH, 0.8 g of PinAc, and 25 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 340 psi (23.8 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 340 psi (23.8 kg / cm ² ) and adding TFE as needed. . A solution obtained by diluting 82.57 g of NB-F-OH and 9.58 g of PinAc to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to an excess amount of hexane while stirring. The precipitate was filtered, washed with hexane and air-dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc, and was slowly added to an excess amount of hexane. The precipitate was filtered, washed with hexane, and dried overnight in a vacuum drier to obtain 57.4 g of a white polymer. The ¹³ C NMR spectrum indicated that the polymer composition was 39% TFE, 47% NB-F-OH, and 14% PinAc. DSC: Tg = 135 ° C. GPC: Mn = 4800; Mw = 8400; Mw / Mn = 1.77. Analytical values: C, 44.86; H, 3.85; F, 38.27.

(Polymer of TFE, NB-F-OH and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 69.6 g of NB-F-OH, 1.72 g of PinAc, and 25 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 320 psi (22.4 kg / cm ² ) throughout the polymerization by applying TFE to a pressure of 320 psi (22.4 kg / cm ² ) and adding TFE as needed. . A solution of 78.54 g of NB-F-OH and 13.14 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to an excess amount of hexane while stirring. The precipitate was filtered, washed with hexane and air-dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc, and was slowly added to an excess amount of hexane. The precipitate was filtered, washed with hexane, and dried overnight in a vacuum drier to obtain 51.6 g of a white polymer. DSC: Tg = 143 ° C. GPC: Mn = 6200; Mw = 9900; Mw / Mn = 1.59. Analytical values: C, 46.77; H, 4.56; F, 33.94.

(Polymer of TFE, NB-F-OH, t-BuAc and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 71.05 g of NB-F-OH, 0.48 g of t-BuAc, 0.22 g of PinAc, and 25 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 340 psi (23.8 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 340 psi (23.8 kg / cm ² ) and adding TFE as needed. . A solution of 82.57 g of NB-F-OH, 5.33 g of t-BuAc, and 3.58 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to excess heptane with stirring. The precipitate was filtered, washed with heptane and air dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc and added slowly to excess heptane. The precipitate was filtered, washed with heptane, and dried in a vacuum drier overnight to obtain 45.3 g of a white polymer. The ¹³ C NMR spectrum showed that the polymer composition was 34% TFE, 45% NB-F-OH, 12% t-BuAc, and 8% PinAc. DSC: Tg = 141 ° C. GPC: Mn = 6800; Mw = 10100; Mw / Mn = 1.49. Analytical values: C, 46.14; H, 4.43; F, 36.91.

(Polymer of TFE, NB-F-OH, MAdA and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 71.05 g of NB-F-OH, 0.72 g of MAdA, 0.30 g of PinAc, and 50 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 325 psi (22.8 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 325 psi (22.8 kg / cm ² ) and adding TFE as needed. . A solution of 85.59 g of NB-F-OH, 7.64 g of MAdA, and 3.00 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to an excess amount of hexane while stirring. The precipitate was filtered, washed with hexane and air-dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc, and was slowly added to an excess amount of hexane. The precipitate was filtered, washed with hexane, and dried overnight in a vacuum drier to obtain 45.6 g of a white polymer. From the ¹³ C NMR spectrum, the polymer composition was found to be TFE 37%, NB-F-OH 49%, MAdA 11% and PinAc 3%. DSC: Tg = 158 ° C. GPC: Mn = 5300; Mw = 9300; Mw / Mn = 1.76. Analytical values: C, 45.56; H, 4.07; F, 38.82.

(Polymer of TFE, NB-F-OH, MAdA and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 71.05 g of NB-F-OH, 0.39 g of MAdA, 0.56 g of PinAc, and 50 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 325 psi (22.8 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 325 psi (22.8 kg / cm ² ) and adding TFE as needed. . A solution of 85.59 g of NB-F-OH, 3.82 g of MAdA, and 5.97 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to excess heptane with stirring. The precipitate was filtered, washed with heptane and air dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc and added slowly to excess heptane. The precipitate was filtered, washed with heptane, and dried overnight in a vacuum drier to obtain 50.5 g of a white polymer. The ¹³ C NMR spectrum showed that the polymer composition was 36% TFE, 46% NB-F-OH, 4% MAdA, and 12% PinAc. DSC: Tg = 127 ° C (very weak transition). GPC: Mn = 4900; Mw = 8900; Mw / Mn = 1.84. Analytical values: C, 45.36; H, 4.03; F, 38.04.

(Polymer of TFE, NB-F-OH, MAdA and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 78.3 g of NB-F-OH, 3.96 g of MAdA, 2.06 g of PinAc, 7.2 g of a tetrahydrofuran chain transfer agent, and 35 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 270 psi (18.9 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 270 psi (18.9 kg / cm ² ) and adding TFE as needed. . A solution of 58.0 g of NB-F-OH, 28.6 g of MAdA, and 14.91 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min over 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to an excess amount of hexane while stirring. The precipitate was filtered, washed with hexane and air-dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc, and was slowly added to an excess amount of hexane. The precipitate was filtered, washed with hexane, and dried overnight in a vacuum drier to obtain 62.6 g of a white polymer. DSC: Tg = 157 ° C. GPC: Mn = 6700; Mw = 12900; Mw / Mn = 1.84. Analytical values: C, 56.04; H, 6.33; F, 22.91.

(Polymer of TFE, NB-F-OH, MAdA and PinAc)
A metal pressure vessel having a capacity of about 270 mL was charged with 78.3 g of NB-F-OH, 5.28 g of MAdA, 1.03 g of PinAc, 7.2 g of a tetrahydrofuran chain transfer agent, and 35 mL of Solkane 365mfc. The vessel was closed, cooled to about −15 ° C., pressurized with nitrogen to 400 psi (28 kg / cm ² ), and vented several times. The reactor contents were heated to 50 ° C. The pressure regulator was set to maintain a pressure of 270 psi (18.9 kg / cm ² ) throughout the polymerization by adding TFE to a pressure of 270 psi (18.9 kg / cm ² ) and adding TFE as needed. . A solution of 58.0 g of NB-F-OH, 38.13 g of MAdA, and 7.45 g of PinAc diluted to 100 mL with Solkane 365 mfc was injected into the reactor at a rate of 0.10 mL / min for 12 hours. Simultaneously with the monomer feed solution, a solution of 7.3 g of Perkadox® 16N and 60 mL of methyl acetate diluted to 100 mL with Solkane 365 mfc over 6 minutes at a rate of 2.0 mL / min, then 8 hours at a rate of 0.1 mL / min. And injected into the reactor. After a reaction time of 16 hours, the vessel was cooled to room temperature and vented to 1 atmosphere. The recovered polymer solution was slowly added to an excess amount of hexane while stirring. The precipitate was filtered, washed with hexane and air-dried. The obtained solid was dissolved in a mixture of THF and Solkane 365 mfc, and was slowly added to an excess amount of hexane. The precipitate was filtered, washed with hexane, and dried overnight in a vacuum drier to obtain 54.6 g of a white polymer. DSC: Tg = 175 ° C. GPC: Mn = 7900; Mw = 14300; Mw / Mn = 1.82. Analytical values: C, 58.07; H, 6.20; F, 21.94.

(Formulation and imaging of polymers of TFE, NB-F-OH, and PinAc)
The following solutions were prepared, magnetically stirred overnight, and filtered through a 0.45 μm PTFE syringe filter before use.
Ingredient Weight (gram)
TFE / NB-F-OH / PinAc polymer of Example 5 1.938
2-Heptanone 12.356
Solution prepared by diluting a 1.0 wt% solution of tetrabutylammonium hydroxide in ethyl lactate 1/1 with 2-heptanone 1.21
Triphenylsulfonium nonaflate dissolved in heptanone filtered through a 0.45 μm PTFE syringe filter
6.496% by weight solution 1.496

  All imaging exposures were performed using an Exittech 157 nm microstepper. The resist formulation was spin coated onto an 8 inch (20.3 cm) Si wafer that was first gas phase primed with hexamethyldisilazane (HMDS) at 90 ° C. The obtained film was soft-baked at 150 ° C. for 60 seconds, that is, pre-exposure bake (PAB), and then the film thickness was measured using a Prometric interferometer. This is described in J.A. A. The Cauchy coefficient obtained by the measurement of the variable angle spectroscopic ellipsometry using the Woollam VU301 variable angle spectroscopic ellipsometer is used. Open-frame exposure with an Exitich stepper (typically with an exposure dose of 100), or a binary mask with a numerical aperture (NA) = 0.6 and partial coherence (σ) = 0.7, or an N.I. A. = 0.6 and σ = 0.3, after image formation using a strong phase shift mask, the wafer was post-exposure baked (PEB) at 110 ° C. for 60 seconds, then Shipley LDD-26W tetramethylammonium hydroxide 2 Paddle development was performed for 60 seconds using .38%. Next, the wafer subjected to the open frame exposure was subjected to thickness measurement with a Prometrix interferometer, and the decrease in thickness with respect to the exposure dose was determined. The imaged wafer was then inspected using a JEOL 7550 top-down and tilt scanning electron microscope (SEM), and in some cases, a cross section was made and inspected using a Hitachi 4500 SEM.

The resist formulation was spin coated on an 8 inch (20.3 cm) Si wafer at a speed of 2032 rpm and PAB at 150 ° C. for 60 seconds to give a film with a measured thickness of 2152 °. The film was then exposed to 157 nm radiation using an Extech stepper using a phase shift mask to obtain a latent image. After exposure, the films were PEBed at 110 ° C. for 60 seconds and then paddle developed with Shipley LDD-26W developer at room temperature for 60 seconds. The resulting image was inspected using a JEOL 7550 SEM. At an exposure dose of 55 mJ / cm ² , the images were found to show dense and isolated features with a resolution of 100 nm.

(Formulation and imaging of polymers of TFE, NB-F-OH, t-BuAc, and PinAc)
The following solutions were prepared, magnetically stirred overnight, and filtered through a 0.45 μm PTFE syringe filter before use.
Ingredient Weight (gram)
1.368 TFE / NB-F-OH / tBA / PinAc polymer of Example 6.
2-heptanone 8.726
Solution prepared by diluting a 1.0 wt% solution of tetrabutylammonium hydroxide in ethyl lactate 1/1 with 2-heptanone 0.850
Triphenylsulfonium nonaflate dissolved in heptanone filtered through a 0.45 μm PTFE syringe filter
6.56% by weight solution of 1.056

The general image forming method of Example 10 was used except that the PEB was set to 130 ° C. The resist formulation was spin coated on an 8 inch (20.3 cm) Si wafer at a speed of 2032 rpm and PAB at 150 ° C. for 60 seconds to give a film with a measured thickness of 2152 °. The film was then exposed to 157 nm radiation using an Extech stepper using a phase shift mask to obtain a latent image. After exposure, the film was PEB at 130 ° C. for 60 seconds, and then paddle developed with Shipley LDD-26W developer at room temperature for 60 seconds. The resulting image was inspected using a JEOL 7550 SEM. At an exposure dose of 42 mJ / cm ² , the image was found to show dense and isolated features with 100 nm resolution.

(Formulation and imaging of polymers of TFE, NB-F-OH, MAdA, and PinAc)
A solution was prepared as in Example 10, except that the polymer used was the TFE / NB-F-OH / MAdA / PinAc polymer of Example 6.

The general image forming method of Example 11 was used except that the PEB was set to 105 ° C. The resist formulation was spin coated on an 8 inch (20.3 cm) Si wafer and PABed at 150 ° C. for 60 seconds to give a film with a measured thickness of 2158 °. The film was then exposed to 157 nm radiation using an Extech stepper using a phase shift mask to obtain a latent image. After exposure, the film was PEB at 105 ° C. for 60 seconds, and then paddle developed with Shipley LDD-26W developer at room temperature for 60 seconds. The resulting image was inspected using a JEOL 7550 SEM. At an exposure dose of 74 mJ / cm ² , the image was found to show 100 nm dense features and 60 nm isolated features.

(Formulation and imaging of polymers of TFE, NB-F-OH, MAdA, and PinAc)
A solution was prepared as in Example 11, except that the polymer used was the TFE / NB-F-OH / MAdA / PinAc polymer of Example 7.

The general image forming method of Example 11 was used except that the PEB was set to 10 ° C. The resist formulation was spin coated on an 8 inch (20.3 cm) Si wafer and PABed at 150 ° C. for 60 seconds to give a film with a measured thickness of 2158 °. The film was then exposed to 157 nm radiation using an Extech stepper using a phase shift mask to obtain a latent image. After exposure, the film was PEB at 105 ° C. for 60 seconds, and then paddle developed with Shipley LDD-26W developer at room temperature for 60 seconds. The resulting image was inspected using a JEOL 7550 SEM. At an exposure dose of 74 mJ / cm ² , the image was found to show 100 nm dense features and 60 nm isolated features.

(Formulation and imaging of polymers of TFE, NB-F-OH, MAdA, and PinAc)
The following solutions were prepared, magnetically stirred overnight, and filtered through a 0.45 μm PTFE syringe filter before use.
Ingredient Weight (gram)
TFE / NB-F-OH / MAdA / PinAc polymer of Example 9 0.869
2-heptanone 5.822
Solution prepared by diluting a 1.0% by weight solution of tetrabutylammonium hydroxide in ethyl lactate 1/1 with 2-heptanone 0.360
Triphenylsulfonium nonaflate dissolved in heptanone filtered through a 0.45 μm PTFE syringe filter
6.49% by weight solution of 0.449

The general image forming method of Example 11 was used except that the PEB was set to 120 ° C. This resist formulation was spin coated on an 8 inch (20.3 cm) Si wafer at a speed of 1918 rpm and PAB at 150 ° C. for 60 seconds to give a film with a measured thickness of 2145 °. The film was then exposed to 157 nm radiation using an Extech stepper using a phase shift mask to obtain a latent image. After exposure, the film was PEB at 120 ° C. for 60 seconds, and then paddle developed with Shipley LDD-26W developer for 60 seconds at room temperature. The resulting image was inspected using a JEOL 7550 SEM. At an exposure dose of 58 mJ / cm ² , the image was found to show 100 nm dense features and 50 nm isolated features.

Although the present invention has been shown and described in detail with reference to preferred embodiments thereof, those skilled in the art will appreciate that various changes in form and detail can be made without departing from the spirit and scope of the invention as defined in the appended claims. You will understand what can be done.

Claims (26)

A photoresist,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) A photoresist comprising a photoactive component.   The photoresist of claim 1, wherein the polymer further comprises a fluoroalcohol group or a protected fluoroalcohol group. Said fluoroalcohol group or protected fluoroalcohol group has the structure -C ( _Rf ) ( _Rf ') OH-, wherein _Rf and _Rf ' are the same or different from one to about 10 carbon atoms. At least one ethylene comprising a fluoroalcohol group, which is a different fluoroalkyl group or R _f and R _f ′ are (CF ₂ ) _n , where n is 2 to 10. 3. The photoresist according to claim 2, wherein the photoresist is derived from an unsaturated compound. The photoresist of claim ₃ , wherein _Rf and _Rf 'are CF3.   The photoresist of claim 1, wherein the hydroxyester functional group is PinAc or PinMAc. A photoresist,
a) The following formula:
_{^{H 2 C = C (X)}} -CO 2 -C (R 1) (R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer comprising at least one repeating unit derived from
[Where,
X = H, C ₁ -C ₆ alkyl, F, or F-substituted C ₁ -C ₆ alkyl;
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) A photoresist comprising a photoactive component.   The photoresist of claim 6, wherein the polymer further comprises a repeating unit derived from an ethylenically unsaturated compound containing at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom. The ethylenically unsaturated compound includes tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, perfluoro- (2,2-dimethyl-1,3-dioxole), perfluoro - _{(2-methylene-4-methyl-1,3-dioxolane), CF 2 = CFO (CF} 2) t CF = CF 2 ( where, t is 1 or 2), and _R f OCF = _CF 2 ( The photoresist of claim 7, wherein _Rf is a saturated fluoroalkyl group having from 1 to about 10 carbon atoms.   The photoresist of claim 6, wherein the polymer comprises a repeating unit derived from a polycyclic ethylenically unsaturated compound. The polycyclic ethylenically unsaturated compound,

The photoresist of claim 9, wherein the photoresist is selected from the group consisting of:   The polymer includes acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, t-butyl acrylate, 2-methyl-2-adamantyl acrylate, 2-methyl-2-norbornyl acrylate, 2-methoxyethyl acrylate, and 2-hydroxyethyl acrylate. It further comprises a monomer selected from the group consisting of ethyl acrylate, 2-cyanoethyl acrylate, glycidyl acrylate, and 2,2,2-trifluoroethyl acrylate, and a repeating unit derived from the corresponding methacrylate monomer. The photoresist according to claim 6.   The photoresist of claim 6, wherein the monomer is selected from the group consisting of t-butyl acrylate and 2-methyl-2-adamantyl acrylate.   The photoresist of claim 6, wherein the polymer further comprises a repeating unit derived from NB-F-OH. A copolymer,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A repeating unit comprising at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) a repeating unit derived from a polycyclic ethylenically unsaturated compound;
c) a repeating unit derived from an ethylenically unsaturated compound containing at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom. The ethylenically unsaturated compound of c) is tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, perfluoro- (2,2-dimethyl-1,3-dioxole) ), perfluoro - _{(2-methylene-4-methyl-1,3-dioxolane), CF 2 = CFO (CF} 2) t CF = CF 2 ( where, t is 1 or 2), and _{R f} 'OCF = CF 2 _(where, R f _'is from 1 carbon atom is about 10 saturated fluoroalkyl group) the copolymer of claim 14, characterized in that it is selected from the group consisting of.   The copolymer of claim 15, wherein said ethylenically unsaturated compound is tetrafluoroethylene. The polycyclic ethylenically unsaturated compound,

15. The copolymer of claim 14, wherein the copolymer is selected from the group consisting of: A photoresist composition,
a) a polymer,
i) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A repeating unit functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
ii) a repeating unit derived from a polycyclic ethylenically unsaturated compound;
iii) a polymer comprising a repeating unit derived from an ethylenically unsaturated compound containing at least one fluorine atom covalently bonded to an ethylenically unsaturated carbon atom; and b) a photoactive component. Resist composition.   The photoresist composition of claim 18, wherein the photoactive component is a photoacid generator.   The photoresist composition of claim 18, further comprising a dissolution inhibitor.   The photoresist composition of claim 18, further comprising a solvent. These solvents, ether esters, ketones, esters, glycol ethers, unsubstituted or substituted hydrocarbon, aromatic hydrocarbon, is selected from fluorinated solvents and the group consisting of supercritical CO ₂ to claim 21, wherein The photoresist composition of any one of the preceding claims.   The composition further comprises at least one additive selected from the group consisting of a base, a surfactant, a resolution enhancer, a fixing agent, a residue inhibitor, a coating aid, a plasticizer, and a Tg (glass transition temperature) regulator. 19. The photoresist composition according to claim 18, wherein A method of producing a photoresist image on a substrate, in order
(W) a step of applying a photoresist composition to the substrate,
a) The following formula:
_{^{-CO 2 -C (R 1) (}} R 2) - [C (R 3) (R 4)] n -C (R 5) (R 6) -OH
A polymer functionalized with at least one hydroxyester function of
[Where,
n = 0, 1, 2, 3, 4 or 5;
R ^{1, R} 2 ₌ C 1 -C ₆ alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 1} and ^{R 2} are taken together, the carbon bonded to ^{R 1} and ^{R 2} Forms a 3 to 8 membered ring, optionally substituted with an ether oxygen, provided that is not at the bridgehead position;
_{^{R 3, R 4 = H,}} C 1 ~C 6 alkyl, _C 1 -C ₆ alkyl substituted with an ether oxygen; or, ^{R 3} and ^{R 4} taken together, substituted by ether oxygen optionally Forming a 3- to 8-membered ring;
_{^{R 5, R 6 = H,}} C 1 ~C 6 alkyl, or an ether oxygen _C 1 -C ₆ alkyl substituted by; or, ^{R 5} and ^{R 6} taken together is substituted with an ether oxygen optionally Or R ¹ and R ⁵ are combined with — [C (R ³ ) (R ⁴ )] n— to form a carbon bonded to R ¹ and R ² Forming a 4- to 8-membered ring, provided that it is not at the bridgehead]
b) at least one photoactive component;
c) applying a photoresist composition comprising: a solvent;
(X) drying the applied photoresist composition to substantially remove the solvent, thereby forming a photoresist layer on the substrate;
(Y) imagewise exposing the photoresist layer to form an image-forming region and a non-image-forming region;
(Z) developing the exposed photoresist layer having imaged and non-imaged areas to form a relief image on the substrate. a) a substrate;
A coated substrate comprising: b) the photoresist composition of claim 18. 26. The coated substrate according to claim 25, wherein said substrate is selected from the group consisting of silicon, silicon oxide, silicon oxynitride, and silicon nitride.